One problem related to engine funny noise has been reported for the 1999 Ford Expedition. The most recently reported issues are listed below.
Pulling out of a convenience store we heard a funny sound and made it to a parking lot of a restaurant. Had to call the insurance company to be towed home. Found out it was spark plug that had blown out. It stripped the threads and is now going to cost a lot to get it fixed, not to mention the towing.